Natural Resources
Conservation Service
-
Search
Major Land Resource Area or ecological site by name and/or ID.
PreviousSectionsNextGeneral information
Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.
Click to explore map
Figure 1. Mapped extent
Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.
MLRA notes
Major Land Resource Area (MLRA): 040X–Sonoran Basin and Range
AZ 40.1 – Upper Sonoran Desert
Elevations range from 2000 to 3200 feet and precipitation averages 10 to 13 inches per year. Vegetation includes saguaro, palo verde, mesquite, creosotebush, triangle bursage, prickly pear, cholla, limberbush, wolfberry, bush muhly, threeawns, ocotillo, and globe mallow. The soil temperature regime is thermic and the soil moisture regime is typic aridic. This unit occurs within the Basin and Range Physiographic Province and is characterized by numerous mountain ranges that rise abruptly from broad, plain-like valleys and basins. Igneous and metamorphic rock classes dominate the mountain ranges and sediments filling the basins represent combinations of fluvial, lacustrine, colluvial and alluvial deposits.Associated sites
R040XA101AZ Basalt Hills 10"-13" p.z.
R040XA103AZ Clayey Slopes 10"-13" p.z.
R040XA105AZ Shallow Hills 10"-13" p.z.
Similar sites
R040XB222AZ Volcanic Hills 7"-10" p.z.
R041XC323AZ Volcanic Hills 12-16" p.z. Loamy
R038XA133AZ Volcanic/Metamorphic Hills 12-16" p.z.
Table 1. Dominant plant species
Tree (1) Parkinsonia microphylla
(2) Carnegia giganteaShrub (1) Simmondsia chinensis
Herbaceous (1) Sphaeralcea ambigua
Physiographic features
This site occurs in the upper elevations of the Sonoran Desert in southern Arizona. Slope aspect is site differentiating at elevations near common resource area boundaries. It occurs on steep hill-slopes and ridge-tops.
Table 2. Representative physiographic features
Landforms (1) Hill
(2) Ridge
(3) Mountain slope
Flooding frequency None Ponding frequency None Elevation 2200 – 4000 ft Slope 15 – 75 % Aspect N, E, S Climatic features
Precipitation in the sub resource area ranges from 10 to 13 inches in the southern part, along the Mexican border with elevations from about 1900 to 3200 feet. Precipitation in the northern part of the resource area ranges from 11 to 14 inches with elevations from about 1700 to 3500 feet. Winter-summer rainfall ratios range from 40%-60% in the southern portions of the land resource unit, to 50%-50% in the central portions, to 60%-40% in the northern part of the land resource unit. As one moves from east to west in this resource area rains become slightly more unpredictable and variable with Coefficients of Variation of annual rainfall equal to 29% at Tucson and 36% at Carefree. Summer rains fall July through Sept., originate in the Gulf of Mexico, and are convective, usually brief, intense thunderstorms. Cool season moisture tends to be frontal, originating in the Pacific and Gulf of California. This winter precipitation falls in widespread storms with long duration and low intensity. Snow is rare and seldom lasts more than an hour or two. May and June are the driest months of the year. Humidity is generally very low.
Winter temperatures are mild, with very few days recording freezing temperatures in the morning. Summer temperatures are warm to hot, with several days in June and July exceeding 105 degrees F.
Both the spring and the summer growing seasons are equally important for perennial grass, forb and shrub growth. Cool and warm season annual forbs and grasses can be common in their respective seasons with above average rainfall. Perennial forage species can remain green throughout the year with available moisture.Table 3 Representative climatic features
Frost-free period (average) 270 days Freeze-free period (average) 0 days Precipitation total (average) 10 in BarLineFigure 2. Monthly precipitation range
BarLineFigure 3. Monthly average minimum and maximum temperature
">Influencing water features
There are no water features associated with this site.
Soil features
These are shallow soils formed on intermediate igneous parent material (Andesite, Dacite, Diorite) related agglomerates, tuffs and breccia. Bedrock is usually hard and unweathered. They are non to slightly calcareous, loamy textured and have well developed covers of gravels, cobbles and stones. Numerous areas of rock outcrop occur intermingled with soil areas. Outcrops can be as high as 35% of the area. Plant-soil moisture relationships are fair to good.
Soils mapped on this site include: in
SSA-645 Aguilla-Carefree MU's Lehmans-72, 73, 104 & 105;
SSA-661 Eastern Pinal Southern Gila counties MU Lehmans-835;
SSA-669 Eastern Pima county MU Lehmans-41;
SSA-703 Tohono O'odham MU's Bosa-40 & Lahitas-40.Table 4. Representative soil features
Parent material (1) Residuum – andesite
Surface texture (1) Very gravelly sandy loam
(2) Very cobbly sandy loam
(3) Very gravelly loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderately rapid to moderate Soil depth 5 – 20 in Surface fragment cover <=3" 40 – 60 % Surface fragment cover >3" 10 – 30 % Available water capacity
(0-40in)1.1 – 2.5 in Calcium carbonate equivalent
(0-40in)0 – 5 % Electrical conductivity
(0-40in)0 – 2 mmhos/cm Sodium adsorption ratio
(0-40in)0 – 2 Soil reaction (1:1 water)
(0-40in)7.4 – 8.2 Subsurface fragment volume <=3"
(Depth not specified)35 – 65 % Subsurface fragment volume >3"
(Depth not specified)0 – 20 % Ecological dynamics
The plant communities found on an ecological site are naturally variable. Composition and production will vary with yearly conditions, location, aspect, and the natural variability of the soils. The Historical Climax Plant Community represents the natural potential plant communities found on relict or relatively undisturbed sites. Other plant communities described here represent plant communities that are known to occur when the site is disturbed by factors such as fire, grazing, or drought.
Production data provided in this site description is standardized to air dry weight at the end of the summer growing season. The plant communities described in this site description are based on near normal rainfall years.
NRCS uses a Similarity Index to compare existing plant communities to the plant communities described here. Similarity Index is determined by comparing the production and composition of a plant community to the production and composition of a plant community described in this site description. To determine Similarity Index, compare the production (air dry weight) of each species to that shown in the plant community description. For each species, count no more than the maximum amount shown for the species, and for each group, count no more than the maximum amount shown for the group. Divide the resulting total by the total normal year production shown in the plant community description. If the rainfall has been significantly above or below normal, use the total production shown for above or below normal years. If field data is not collected at the end of the summer growing season, then the field data must be corrected to the end of the year production before comparing it to the site description. The growth curve can be used as a guide for estimating production at the end of the summer growing season.
State and transition model
Custom diagramStandard diagram
Figure 4. State and Transition, Volcanic Hills 10-13" pz.
More interactive model formats are also available. View Interactive Models
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textEcosystem states
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 5 submodel, plant communities
State 6 submodel, plant communities
State 1
Historical Climax Plant CommunityCommunity 1.1
Historical Climax Plant CommunityThe potential plant community on this site is a diverse mixture of desert shrubs, trees, cacti and perennial grasses and forbs. The aspect is shrubland.
With continuous, heavy grazing, herbaceous and suffrutescent forage species are removed from the plant community and shrubs like triangle bursage, white brittle bush, whitethorn acacia, hopseed bush, prickly pear and cholla can increase to occupy the vacancy. Well developed gravel and cobble covers protect the soil from erosion and protect forage species from heavy utilization. The dark color of surface rocks warms the soil allowing plants to grow later into the fall with available moisture and to green up earlier in the spring. Areas of rock outcrop tend to magnify water received by adjacent soil areas. Percent bare ground on the site ranges from 5 to 20. Plant populations for major shrub species range form 10 to 300 per acre for jojoba, 10 to 200 per acre for creosotebush or whitethorn, 20 to 250 per acre for littleleaf paloverde, 50 to 200 ocotillo per acre, 50 to 200 wolfberry per acre, 50 to 300 mormon tea per acre, 10 to 200 mint bush per acre and 0 to 20 saguaro per acre.
North exposures have a higher percentage cover of perennial grasses and forbs than warm exposures. Grass cover ranges from 0-10% on north slopes and 0-2% on south slopes. Forb cover ranges from 1-25% on north slopes and 0-6% on south slopes. Warm exposures have a higher percentage of trees and succulents than north slopes. The half shrub community on north slopes is dominated by species like calliandra, goldeneye, mintbush and mormon tea while on south slopes brittlebush, ratany, limberbush and bursage are dominant. Jojoba will have its higher cover on north aspects while southern aspects will have more ocotillo, whitethorn and wolfberry. The percent of annual forbs and grasses in the plant community can range from 5% in dry years to nearly 70% in very wet winters or summers. The yearly production of annuals ranges from 20 lbs per acre to over 1500 lbs. per acre (from dry year to wet year).
Severe drought can reduce the cover of perennial grasses and suffrutescent forbs to less than 1%. Drought can also reduce the cover of sub-shrubs like brittlebush and bursage.
The dynamics of Saguaro on this site is unlike the 200-300 year cycle found on deep upland sites in the Upper Sonoran desert. Saguaro recruitment can occur in any favorable year due to numerous rocky habitats favorable for establishment. Saguaro populations tend to be multi-aged and persistent on this site although very favorable years for establishment may result in very heavy stands on some slopes many years later.Figure 5. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Forb 50 75 635 Shrub/Vine 102 400 515 Grass/Grasslike 25 100 450 Tree 65 200 250 Total 242 775 1850 Table 6. Soil surface cover
Tree basal cover 0-0% Shrub/vine/liana basal cover 0-10% Grass/grasslike basal cover 0-0% Forb basal cover 0-0% Non-vascular plants 0% Biological crusts 0-10% Litter 10-70% Surface fragments >0.25" and <=3" 30-60% Surface fragments >3" 10-40% Bedrock 0-20% Water 0% Bare ground 10-30% Table 7. Canopy structure (% cover)
Height Above Ground (ft) Tree Shrub/Vine Grass/
GrasslikeForb <0.5 – 0-1% 0-15% 0-15% >0.5 <= 1 – 0-10% 1-15% 1-20% >1 <= 2 – 2-12% 0-5% 1-5% >2 <= 4.5 0-1% 1-5% 0-1% 0-1% >4.5 <= 13 0-15% 0-1% – – >13 <= 40 0-1% – – – >40 <= 80 – – – – >80 <= 120 – – – – >120 – – – – Figure 6. Plant community growth curve (percent production by month). AZ4011 , 40.1 10-13" p.z. hill sites. Growth begins in the late winter, goes semi-dormant in the drought period of late May through early July, growth continues in the summer through early fall..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 0 5 15 20 5 5 10 15 15 5 5 0 State 2
Native trees, cacti, shrubs and fireCommunity 2.1
Native trees, cacti, shrubs and fireThis plant community occurs as a result of a single hot season fire. Paloverde and saguaro can be severely impacted and may take long periods of time (30-50 years) to recover to pre-fire levels. Perennial and annual grasses and forbs dominate the community for some time until shrubs like wolfberry, ocotillo and jojoba can recover.
This plant community can produce enough herbaceous fuel from native species of grasses and / or forbs to carry fire in El Nino years or after unusually wet summers. The natural incidence of fire in this MLRA is very low and fires are much more common from man-made ignitions. Areas of the site close to urban zones or along heavily travelled roads and highways will experience a higher rate of fires.State 3
Exotic perennial grasses with nativesCommunity 3.1
Exotic perennial grasses with nativesThis community occurs where bufflegrass and / or fountain grass invade the native plant community. These species occupy the niches of low shrubs like false mesquite, janusia, twinberry or triangle goldeneye and can displace species like wolfberry and jojoba.
State 4
Exotic perennial grasses and fireCommunity 4.1
Exotic perennial grasses and fireThis community occurs where a native plant community that has been invaded by bufflegrass or fountain grass has burned one or more times. Increasing amounts of bufflegrass leads to more uniform fine fuels. In areas adjacent to roads and urban areas the risk of repeated fires will increase. As fire frequency increases the dominance of the exotic grasses increase.
State 5
Native plant community with exotic annualsCommunity 5.1
Native plant community with exotic annualsThis plant community occurs where the native community has been invaded by red brome and / or schismus. Red brome occupies the niche of the native winter annual forbs and grasses. This exotic annual grass will fluctuate from nearly nothing in a dry winter to dominance of the understory plant community in a El Nino winter.
State 6
Exotic annuals and fireCommunity 6.1
Exotic annuals and fireThis plant community occurs where a native plant community which has been invaded by red brome has burned repeatedly. As fires become more frequent the native trees, shrubs and succulents are removed from the plant community and red brome becomes dominant. In areas of the site near urban areas and along heavily travelled roads this will be a more common occurence due to an increased source of ignitions.
Additional community tables
Table 8. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Dominant short grasses 5–60 slender grama BORE2 Bouteloua repens 1–50 – curly-mesquite HIBE Hilaria belangeri 0–50 – slim tridens TRMU Tridens muticus 1–20 – 2 Dominant mid grasses 15–110 sideoats grama BOCU Bouteloua curtipendula 5–50 – tobosagrass PLMU3 Pleuraphis mutica 5–50 – tanglehead HECO10 Heteropogon contortus 5–40 – bush muhly MUPO2 Muhlenbergia porteri 1–30 – desert needlegrass ACSP12 Achnatherum speciosum 0–25 – cane bluestem BOBA3 Bothriochloa barbinodis 0–10 – Arizona cottontop DICA8 Digitaria californica 0–10 – 3 Miscellaneous perennial grasses 2–30 spidergrass ARTE3 Aristida ternipes 1–25 – Parish's threeawn ARPUP5 Aristida purpurea var. parishii 1–15 – purple threeawn ARPU9 Aristida purpurea 0–10 – red grama BOTR2 Bouteloua trifida 0–10 – Hall's panicgrass PAHA Panicum hallii 0–10 – big galleta PLRI3 Pleuraphis rigida 0–10 – large-spike bristlegrass SEMA5 Setaria macrostachya 0–5 – black grama BOER4 Bouteloua eriopoda 0–5 – blue grama BOGR2 Bouteloua gracilis 0–5 – hairy grama BOHI2 Bouteloua hirsuta 0–2 – fall witchgrass DICO6 Digitaria cognata 0–2 – southwestern bristlegrass SESC2 Setaria scheelei 0–2 – plains bristlegrass SEVU2 Setaria vulpiseta 0–2 – muttongrass POFE Poa fendleriana 0–2 – prairie Junegrass KOMA Koeleria macrantha 0–2 – common wolfstail LYPH Lycurus phleoides 0–2 – Wright's threeawn ARPUW Aristida purpurea var. wrightii 0–2 – Havard's threeawn ARHA3 Aristida havardii 0–2 – sand dropseed SPCR Sporobolus cryptandrus 0–1 – squirreltail ELELE Elymus elymoides ssp. elymoides 0–1 – nineawn pappusgrass ENDE Enneapogon desvauxii 0–1 – low woollygrass DAPU7 Dasyochloa pulchella 0–1 – 4 Annual grasses 2–400 mucronate sprangeltop LEPAB Leptochloa panicea ssp. brachiata 0–200 – Mexican panicgrass PAHI5 Panicum hirticaule 0–125 – sixweeks threeawn ARAD Aristida adscensionis 1–100 – needle grama BOAR Bouteloua aristidoides 0–50 – sixweeks grama BOBA2 Bouteloua barbata 0–50 – Rothrock's grama BORO2 Bouteloua rothrockii 0–50 – prairie threeawn AROL Aristida oligantha 0–25 – Eastwood fescue VUMIC Vulpia microstachys var. ciliata 0–25 – Pacific fescue VUMIP Vulpia microstachys var. pauciflora 0–25 – sixweeks fescue VUOC Vulpia octoflora 1–25 – Mexican sprangletop LEFUU Leptochloa fusca ssp. uninervia 0–25 – Bigelow's bluegrass POBI Poa bigelovii 0–10 – delicate muhly MUFR Muhlenbergia fragilis 0–10 – littleseed muhly MUMI Muhlenbergia microsperma 0–10 – witchgrass PACA6 Panicum capillare 0–5 – Grisebach's bristlegrass SEGR6 Setaria grisebachii 0–5 – Madagascar dropseed SPPY2 Sporobolus pyramidatus 0–2 – Arizona signalgrass URAR Urochloa arizonica 0–2 – Arizona brome BRAR4 Bromus arizonicus 0–2 – feather fingergrass CHVI4 Chloris virgata 0–2 – bearded cupgrass ERAR5 Eriochloa aristata 0–2 – canyon cupgrass ERLE7 Eriochloa lemmonii 0–2 – desert lovegrass ERPEM Eragrostis pectinacea var. miserrima 0–2 – tufted lovegrass ERPEP2 Eragrostis pectinacea var. pectinacea 0–2 – little barley HOPU Hordeum pusillum 0–2 – goldentop grass LAAU Lamarckia aurea 0–2 – fragilegrass AETE Aegopogon tenellus 0–1 – Forb5 Parasites 1–15 mesquite mistletoe PHCA8 Phoradendron californicum 1–10 – bigseed alfalfa dodder CUIN Cuscuta indecora 0–5 – 6 Dominant perennial forbs 40–70 slender janusia JAGR Janusia gracilis 10–25 – rough menodora MESC Menodora scabra 5–25 – desert globemallow SPAM2 Sphaeralcea ambigua 2–25 – brownplume wirelettuce STPA4 Stephanomeria pauciflora 1–10 – longflower tube tongue JULO3 Justicia longii 0–10 – narrowleaf silverbush ARLA12 Argythamnia lanceolata 1–10 – weakleaf bur ragweed AMCO3 Ambrosia confertiflora 1–5 – dwarf Indian mallow ABPA3 Abutilon parvulum 0–5 – Parry's false prairie-clover MAPA7 Marina parryi 0–5 – lacy tansyaster MAPIP4 Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida 1–5 – wishbone-bush MILAV Mirabilis laevis var. villosa 0–5 – cockroachplant HACR3 Haplophyton crooksii 0–5 – slender poreleaf POGR5 Porophyllum gracile 1–5 – Coues' cassia SECO10 Senna covesii 1–5 – desert rosemallow HICO Hibiscus coulteri 2–4 – brownfoot ACWR5 Acourtia wrightii 0–4 – dense ayenia AYMI Ayenia microphylla 0–4 – Arizona wrightwort CAAR7 Carlowrightia arizonica 0–4 – bluedicks DICA14 Dichelostemma capitatum 0–3 – white sagebrush ARLU Artemisia ludoviciana 0–2 – San Felipe dogweed ADPO Adenophyllum porophylloides 0–2 – trailing windmills ALIN Allionia incarnata 0–2 – Parry's beardtongue PEPA24 Penstemon parryi 1–2 – Louisiana vetch VILUL2 Vicia ludoviciana ssp. ludoviciana 0–1 – pelotazo ABIN Abutilon incanum 0–1 – perennial rockcress ARPE2 Arabis perennans 0–1 – spurge EUPHO Euphorbia 0–1 – California suncup CACA32 Camissonia californica 0–1 – desert larkspur DEPA Delphinium parishii 0–1 – tall mountain larkspur DESC Delphinium scaposum 0–1 – 7 Annual forbs 5–470 bristly fiddleneck AMTE3 Amsinckia tessellata 0–100 – California poppy ESCAM Eschscholzia californica ssp. mexicana 0–100 – Coulter's lupine LUSP2 Lupinus sparsiflorus 0–100 – thelypody THELY Thelypodium 0–50 – Arizona poppy KAGR Kallstroemia grandiflora 0–50 – western tansymustard DEPI Descurainia pinnata 1–50 – exserted Indian paintbrush CAEXE Castilleja exserta ssp. exserta 0–25 – phacelia PHACE Phacelia 0–25 – woolly tidestromia TILA2 Tidestromia lanuginosa 0–10 – sleepy silene SIAN2 Silene antirrhina 0–10 – coastal bird's-foot trefoil LOSAB Lotus salsuginosus var. brevivexillus 0–10 – milkvetch ASTRA Astragalus 0–10 – American wild carrot DAPU3 Daucus pusillus 0–10 – goosefoot CHENO Chenopodium 0–10 – shaggyfruit pepperweed LELA Lepidium lasiocarpum 0–10 – miniature woollystar ERDI2 Eriastrum diffusum 0–5 – New Mexico thistle CINE Cirsium neomexicanum 0–5 – carelessweed AMPA Amaranthus palmeri 0–5 – desert Indianwheat PLOV Plantago ovata 1–5 – buckwheat ERIOG Eriogonum 1–5 – combseed PECTO Pectocarya 0–5 – shrubby deervetch LORI3 Lotus rigidus 1–3 – plains blackfoot MELE2 Melampodium leucanthum 0–2 – cryptantha CRYPT Cryptantha 0–2 – spreading fleabane ERDI4 Erigeron divergens 0–2 – crestrib morning-glory IPCO2 Ipomoea costellata 0–2 – redstar IPCO3 Ipomoea coccinea 0–2 – desert trumpet ERIN4 Eriogonum inflatum 0–1 – Arizona cottonrose LOAR12 Logfia arizonica 0–1 – Gordon's bladderpod LEGO Lesquerella gordonii 0–1 – spurge EUPHO Euphorbia 0–1 – California fagonbush FALA Fagonia laevis 0–1 – fringed twinevine FUCYC Funastrum cynanchoides ssp. cynanchoides 0–1 – Davis Mountain mock vervain GLBIC Glandularia bipinnatifida var. ciliata 0–1 – paleface HIDE Hibiscus denudatus 0–1 – Newberry's velvetmallow HONE Horsfordia newberryi 0–1 – hyssopleaf sandmat CHHY3 Chamaesyce hyssopifolia 0–1 – flatcrown buckwheat ERDE6 Eriogonum deflexum 0–1 – desert marigold BAMU Baileya multiradiata 0–1 – scarlet spiderling BOCO Boerhavia coccinea 0–1 – spiderling BOERH2 Boerhavia 0–1 – hoary bowlesia BOIN3 Bowlesia incana 0–1 – fringed redmaids CACI2 Calandrinia ciliata 0–1 – naked mariposa lily CANU2 Calochortus nudus 0–1 – whitemargin sandmat CHAL11 Chamaesyce albomarginata 0–1 – brittle spineflower CHBR Chorizanthe brevicornu 0–1 – tuber anemone ANTU Anemone tuberosa 0–1 – New Mexico silverbush ARNE2 Argythamnia neomexicana 0–1 – largeflower onion ALMA4 Allium macropetalum 0–1 – common fiddleneck AMMEI2 Amsinckia menziesii var. intermedia 0–1 – blazingstar MENTZ Mentzelia 0–1 – Lindley's silverpuffs MILI5 Microseris lindleyi 0–1 – green carpetweed MOVE Mollugo verticillata 0–1 – glandular threadplant NEGL Nemacladus glanduliferus 0–1 – desert tobacco NIOBO Nicotiana obtusifolia var. obtusifolia 0–1 – evening primrose OENOT Oenothera 0–1 – Florida pellitory PAFL3 Parietaria floridana 0–1 – Emory's rockdaisy PEEM Perityle emoryi 0–1 – Coulter's lyrepod LYCO4 Lyrocarpa coulteri 0–1 – tansyaster MACHA Machaeranthera 0–1 – whitestem blazingstar MEAL6 Mentzelia albicaulis 0–1 – glandleaf milkwort POMA7 Polygala macradenia 0–1 – New Mexico plumeseed RANE Rafinesquia neomexicana 0–1 – chia SACO6 Salvia columbariae 0–1 – Leiberg stonecrop SELE Sedum leibergii 0–1 – ragwort SENEC Senecio 0–1 – bean PHASE Phaseolus 0–1 – orange fameflower PHAU13 Phemeranthus aurantiacus 0–1 – Arizona popcornflower PLAR Plagiobothrys arizonicus 0–1 – silverleaf nightshade SOEL Solanum elaeagnifolium 0–1 – lyreleaf jewelflower STCA5 Streptanthus carinatus 0–1 – woollyhead neststraw STMI2 Stylocline micropoides 0–1 – sand fringepod THCU Thysanocarpus curvipes 0–1 – vervain VERBE Verbena 0–1 – 8 Ferns and fern allies 5–80 Arizona spikemoss SEAR2 Selaginella arizonica 2–75 – cliffbrake PELLA Pellaea 1–5 – lipfern CHEIL Cheilanthes 1–5 – cloak fern NOTHO Notholaena 0–2 – Shrub/Vine9 Dominant low shrubs 30–200 triangle bur ragweed AMDE4 Ambrosia deltoidea 0–40 – brittlebush ENFA Encelia farinosa 0–30 – broom snakeweed GUSA2 Gutierrezia sarothrae 1–25 – bastardsage ERWR Eriogonum wrightii 0–15 – Parish's goldeneye VIPA14 Viguiera parishii 2–15 – Eastern Mojave buckwheat ERFA2 Eriogonum fasciculatum 1–15 – fairyduster CAER Calliandra eriophylla 5–15 – pelotazo ABIN Abutilon incanum 1–15 – California copperleaf ACCA3 Acalypha californica 0–5 – rayless goldenhead ACSP Acamptopappus sphaerocephalus 0–5 – sweetbush BEJU Bebbia juncea 0–5 – Coulter's brickellbush BRCO Brickellia coulteri 1–5 – ragged rockflower CRBI2 Crossosoma bigelovii 1–5 – turpentine bush ERLA12 Ericameria laricifolia 0–5 – rock sage SAPI2 Salvia pinguifolia 0–5 – American threefold TRCA8 Trixis californica 1–5 – littleleaf ratany KRER Krameria erecta 0–5 – white ratany KRGR Krameria grayi 0–5 – slender poreleaf POGR5 Porophyllum gracile 0–2 – whitestem paperflower PSCO2 Psilostrophe cooperi 0–2 – Mexican bladdersage SAME Salazaria mexicana 0–2 – Mojave sage SAMO3 Salvia mohavensis 0–2 – starry bedstraw GAST Galium stellatum 0–2 – desert rosemallow HICO Hibiscus coulteri 0–2 – toothleaf goldeneye VIDE3 Viguiera dentata 0–2 – woody crinklemat TICAC Tiquilia canescens var. canescens 0–2 – Mojave woodyaster XYTOT Xylorhiza tortifolia var. tortifolia 0–2 – desert zinnia ZIAC Zinnia acerosa 0–2 – Chihuahuan brickellbush BRFL Brickellia floribunda 0–2 – rough brickellbush BRMIS Brickellia microphylla var. scabra 0–2 – desert yellow fleabane ERLI Erigeron linearis 0–1 – Sonoran croton CRSO Croton sonorae 0–1 – 12 Succulents 40–130 saguaro CAGI10 Carnegiea gigantea 5–75 – cactus apple OPEN3 Opuntia engelmannii 15–45 – staghorn cholla CYVE3 Cylindropuntia versicolor 1–20 – banana yucca YUBA Yucca baccata 0–15 – purple pricklypear OPMA8 Opuntia macrocentra 0–10 – tulip pricklypear OPPH Opuntia phaeacantha 1–10 – buck-horn cholla CYAC8 Cylindropuntia acanthocarpa 0–10 – Schott's century plant AGSC3 Agave schottii 0–10 – teddybear cholla CYBI9 Cylindropuntia bigelovii 0–5 – jumping cholla CYFUF Cylindropuntia fulgida var. fulgida 0–5 – candy barrelcactus FEWI Ferocactus wislizeni 1–5 – senita cactus PASC14 Pachycereus schottii 0–5 – organpipe cactus STTH3 Stenocereus thurberi 0–5 – Leding's hedgehog cactus ECLE2 Echinocereus ledingii 0–3 – Christmas cactus CYLE8 Cylindropuntia leptocaulis 0–2 – Graham's nipple cactus MAGR9 Mammillaria grahamii 0–2 – Thornber's nipple cactus MATH Mammillaria thornberi 0–2 – beavertail pricklypear OPBA2 Opuntia basilaris 0–2 – dollarjoint pricklypear OPCH Opuntia chlorotica 0–2 – common sotol DAWH2 Dasylirion wheeleri 0–2 – desert agave AGDE Agave deserti 0–2 – Leconte's barrel cactus FECYL Ferocactus cylindraceus var. lecontei 0–2 – Santa Rita pricklypear OPSA Opuntia santa-rita 0–2 – Emory's barrel cactus FEEM Ferocactus emoryi 0–1 – Engelmann's hedgehog cactus ECEN Echinocereus engelmannii 0–1 – redspine fishhook cactus ECER2 Echinomastus erectocentrus 0–1 – pinkflower hedgehog cactus ECFA Echinocereus fasciculatus 0–1 – Arizona pencil cholla CYAR14 Cylindropuntia arbuscula 0–1 – rainbow cactus ECPE Echinocereus pectinatus 0–1 – spinystar ESVIV Escobaria vivipara var. vivipara 0–1 – 13 Dominant large shrubs 30–150 jojoba SICH Simmondsia chinensis 10–100 – ocotillo FOSP2 Fouquieria splendens 5–60 – whitethorn acacia ACCO2 Acacia constricta 1–50 – catclaw acacia ACGR Acacia greggii 5–30 – Berlandier's wolfberry LYBE Lycium berlandieri 5–25 – Wright's beebrush ALWR Aloysia wrightii 1–10 – spiny hackberry CEEH Celtis ehrenbergiana 1–10 – creosote bush LATRT Larrea tridentata var. tridentata 1–10 – water jacket LYAN Lycium andersonii 0–5 – snapdragon penstemon KEANM Keckiella antirrhinoides ssp. microphylla 0–5 – Arizona desert-thorn LYEX Lycium exsertum 1–5 – Warnock's snakewood COWA Condalia warnockii 0–5 – stretchberry FOPUP Forestiera pubescens var. pubescens 0–3 – desert ceanothus CEGR Ceanothus greggii 0–3 – alderleaf mountain mahogany CEMO2 Cercocarpus montanus 0–3 – red barberry MAHA4 Mahonia haematocarpa 0–3 – catclaw mimosa MIACB Mimosa aculeaticarpa var. biuncifera 0–3 – Mexican cliffrose PUME Purshia mexicana 0–3 – sugar sumac RHOV Rhus ovata 0–3 – skunkbush sumac RHTR Rhus trilobata 0–3 – Sonoran scrub oak QUTU2 Quercus turbinella 0–2 – Schott's pygmycedar PESC4 Peucephyllum schottii 0–2 – Nevada jointfir EPNE Ephedra nevadensis 0–2 – cliff fendlerbush FERU Fendlera rupicola 0–2 – 14 Miscellaneous shrubs 2–35 Las Animas nakedwood COCA18 Colubrina californica 0–5 – sangre de cristo JACA2 Jatropha cardiophylla 0–5 – Arizona mimosa MIDIL Mimosa distachya var. laxiflora 0–5 – Ajo Mountain scrub oak QUAJ Quercus ajoensis 0–5 – arrow poision plant SEBI9 Sebastiania bilocularis 0–2 – Lemmon's ragwort SELE8 Senecio lemmonii 0–2 – Schott's yellowhood NISC Nissolia schottii 0–2 – Florida hopbush DOVI Dodonaea viscosa 0–2 – Tahitian kidneywood EYOR Eysenhardtia orthocarpa 0–2 – desert lavender HYEM Hyptis emoryi 0–2 – beloperone JUCA8 Justicia californica 0–2 – Goodding's tansyaster MAPIG2 Machaeranthera pinnatifida ssp. gooddingii var. gooddingii 0–2 – lacy tansyaster MAPIP4 Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida 0–2 – mouse's eye BEMY Bernardia myricifolia 0–2 – fragrant bursera BUFA Bursera fagaroides 1–2 – Arizona wrightwort CAAR7 Carlowrightia arizonica 0–2 – fourwing saltbush ATCA2 Atriplex canescens 0–2 – shortleaf baccharis BABR Baccharis brachyphylla 0–2 – yerba de pasmo BAPT Baccharis pteronioides 0–2 – desertbroom BASA2 Baccharis sarothroides 0–1 – cattle saltbush ATPO Atriplex polycarpa 0–1 – knifeleaf condalia COSP3 Condalia spathulata 0–1 – Arizona rosewood VACA5 Vauquelinia californica 0–1 – lotebush ZIOB Ziziphus obtusifolia 0–1 – prairie acacia ACANH Acacia angustissima var. hirta 0–1 – whitestem milkweed ASAL Asclepias albicans 0–1 – horsetail milkweed ASSU2 Asclepias subverticillata 0–1 – Tree15 Trees 65–250 yellow paloverde PAMI5 Parkinsonia microphylla 10–200 – desert ironwood OLTE Olneya tesota 0–100 – velvet mesquite PRVE Prosopis velutina 0–50 – crucifixion thorn CAHO3 Canotia holacantha 0–15 – Table 9. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 10. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 11. Community 4.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 12. Community 5.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 13. Community 6.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Steep slopes, very cobbly surfaces and numerous areas of rock outcrop hinder livestock distribution. The site is not well suited to grazing by cows in the hot season except in areas where ridges trend north-south and western exposures are shady in the morning and eastern exposures in the afternoon. In such cases, distribution will be fairly good even in the summer. South facing slopes are used more in the winter due to warm temperatures and early spring greenup. North aspects, being shady and cooler, are used more in the fall due to a longer green season. The plant community has an excellent variety of browse, perennial grasses and forbs providing adequate nutrition throughout the year. Herbaceous forage is high quality due to soils with high exchangeable bases. Seep and canyon water are usually available in the winter-spring rainy season and also for short periods in the summer rainy season. Areas of slick-rock outcrop and hard rock in canyon bottoms offer good opportunity for tricktank water developments. Bluff and rimrock outcrops can form natural barriers with the addition of minimal actual fence construction.
Seasonally available water, forage diversity, cover and topography make this site home to a great variety of wildlife including the larger desert mammals. Large areas of bluff and rimrock outcrop make this site a favorite of desert bighorn sheep. Water developemts are especially important to larger mammals to make the seasonal supplies more permanent. The desert tortoise dens on cobble covered southern exposures in the winter.Hydrological functions
This site is a fair producer of runoff due to steep slopes and shallow soils. Very gravelly and cobbly soil surfaces tend to hold water on the site. In areas with lots of rock outcrop there is a potential to develop water sources using rock catchments.
Recreational uses
Hunting, hiking, bird watching, photography, horseback riding, rock hounding
Wood products
Some paloverde, ironwood and mesquite for camp-fires and branding fires.
Other products
Stones and cobbles, saguaro ribs, cholla skeletons. Tradtional foods like saguaro fruits, prickly pear tunas, cactus flower buds and jojoba nuts. Traditional herbs like coyote tobacco, mint bush, club moss, globe mallow and limberbush.
Supporting information
Inventory data references
Range 417s include 3 in excellent condition and 3 in good condition.
Type locality
Location 1: Pima County, AZ Township/Range/Section T14S R12E S10 General legal description Tucson FO - Tucson Mtn. Park - Gates Pass Location 2: Pima County, AZ General legal description Sells Field Office - South Mountain 32 degrees 00' X 112 degrees 9' Location 3: Pima County, AZ General legal description Sells Field Office - Artesia Mtn. 31 degrees 52' 30" X 111 degrees 51' 30" Location 4: Gila County, AZ Township/Range/Section T4S R17E S23 General legal description San Carlos FO - Mineral Strip - Deer Creek Location 5: Maricopa County, AZ Township/Range/Section T1N R10E S35 General legal description Chandler FO - Quarter Circle U Ranch, Frazier Pas. Location 6: Pinal County, AZ Township/Range/Section T9S R9E S15 General legal description Casa Grande FO - Picacho Peak State Park Location 7: Pima County, AZ UTM zone N UTM northing 3615043.46 UTM easting 373662.66 General legal description Barry Goldwater Gunnery Range, Sand Tank Mountains, Sonoran Desert National Monument Location 8: Pima County, AZ Township/Range/Section T14S R13E S15 General legal description Tumamoc Hills, UA Desert Botanical Laboratory, ungrazed since 1906 Other references
Vegetation change and plant demography in permanent plots in the Sonoran Desert. Deb Goldberg, Ray Turner. Ecology 67(3), 1986, pp. 695-712.
Effects of drought on shrub survival and longevity in the northern Sonoran Desert. Janice Bowers. Journal of the Torrey Botanical Society 132(3), 2005, pp. 421-431.
The Changing Mile Re-visited. Ray Turner, Robert Webb. University of Arizona press, 2003.
Exotic plants at the desert Laboratory, Tucson, Arizona. Tony Burgess, Janice Bowers and Ray Turner. Madrono, 38(2). 1991, pp. 96-114.Contributors
C..Michaels
Dan Robinett
Larry D. EllicottRangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) Dave Womack, Dan Robinett, Emilio Carrillo Contact for lead author NRCS Tucson Area Office Date 12/13/2005 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
-
Number and extent of rills:
Rills are present on this site with high gravel cover but follow fractures, bedding planes and joints in the bedrock parent materials. Soils with high rock cover have no natural rills. -
Presence of water flow patterns:
Uncommon; broken primarily by high rock and gravel cover. -
Number and height of erosional pedestals or terracettes:
Pedestals are uncommon on perennial grass and shrubs (1-2 per 50 plants and no more than 1 inch of root exposed); limited soil material not conducive to forming continuous stands of plants that promote terracettes; high rock cover forms limited natural terracettes. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Estimated at 1-2%. Gravel cover 90-95%, rock 2-3%. Some soils may have 90-95% rock cover. -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None -
Amount of litter movement (describe size and distance expected to travel):
Woody litter stays in place, herbaceous litter transported in limited flow paths. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Expect values of 1-2 in canopy interspaces, and 4-5 under plant canopies. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak thin platy to weak granular; thickness to 5 inches. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Canopy cover = 26%; 35-40% of canopy cover is shrubs, 20-25% half shrubs, 15-20% paloverde, 7-8% succulents, 3-4% perennial grass, 3-4% perennial forbs. Cover is well dispersed throughout the site. North facing slopes may have tree and shrub cover values reversed versus above values and higher values for succulents. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None -
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
shrubs > half shrubs > trees > succulents > perennial grasses and forbs (Note: In El Nino years, annual forbs and grasses are #1 in above ground weight). North slopes may have trees > succulents > half shrubs > shrubs > perennial forbs > perennial grasses.Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
3 and 15% canopy mortality of triangle bursage and jojoba, respectively at Gates Pass west slope. 5-10% mortality of bursage at Tumamoc Hill north slope. -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
242 lbs/ac unfavorable precipitation; 775 lbs/ac normal precipitation; 1850 lbs/ac favorable precipitation -
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
Filaree, Red brome, bufflegrass -
Perennial plant reproductive capability:
Not impaired for shrubs, drought impaired for perennial grasses and forbs.
Print Options
Sections
Font
AAAAOther
PrintThe Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
Accessibility statement
